What's New in Morphir CLI Preview

This page highlights the major new features in the Morphir CLI Preview.

WebAssembly Interface Types (WIT) Support

The CLI Preview introduces full support for WIT, the interface definition language for WebAssembly components. This enables Morphir to serve as a bridge between WIT and other ecosystems.

Why WIT?

WebAssembly Interface Types (WIT) is becoming the standard for defining component interfaces in the WebAssembly ecosystem. By supporting WIT, Morphir can:

• Import WIT contracts and validate them against Morphir models
• Export Morphir types to WIT for WebAssembly component generation
• Round-trip validate conversions between WIT and Morphir IR

The WIT Pipeline

┌─────────────┐         ┌──────────────┐         ┌─────────────┐
│  WIT File   │──make──▶│  Morphir IR  │──gen───▶│  WIT File   │
└─────────────┘         └──────────────┘         └─────────────┘
                               │
                               ▼
                        ┌──────────────┐
                        │    Other     │
                        │   Backends   │
                        └──────────────┘

The pipeline follows Morphir's established patterns:

• make: Frontend compilation (WIT → IR)
• gen: Backend generation (IR → WIT)
• build: Full pipeline with validation

Example: WIT to Morphir IR

// api.wit
package mycompany:api;

interface user-service {
    record user {
        id: u64,
        name: string,
        email: string,
    }

    get-user: func(id: u64) -> option<user>;
    create-user: func(name: string, email: string) -> user;
}

morphir wit make api.wit -o api.ir.json

The IR captures:

• Package namespace (mycompany) and name (api)
• Record types with fields
• Function signatures

JSONL Batch Processing

The CLI Preview adds JSONL (JSON Lines) support for efficient batch processing and streaming workflows.

Why JSONL?

JSONL is ideal for:

• CI/CD pipelines - Each result is a separate JSON object
• Streaming - Process results as they arrive
• Parallel processing - Split input across workers
• Error isolation - One failure doesn't affect others

Single Source with JSONL Output

morphir wit make -s "package a:b; interface foo { x: func(); }" --jsonl

Output:

{"success":true,"typeCount":0,"valueCount":1,"module":{"values":[{"name":"X"}],"sourcePackage":{"namespace":"a","name":"b"}}}

Batch Processing Multiple Sources

Create an input file with one JSON object per line:

{"name": "user-api", "source": "package app:users; interface users { get-user: func(id: u64) -> string; }"}
{"name": "order-api", "source": "package app:orders; interface orders { create-order: func() -> u64; }"}
{"name": "inventory", "file": "./wit/inventory.wit"}

Process all at once:

morphir wit make --jsonl-input apis.jsonl --jsonl

Output (one line per input):

{"name":"user-api","success":true,"typeCount":0,"valueCount":1,"module":{...}}
{"name":"order-api","success":true,"typeCount":0,"valueCount":1,"module":{...}}
{"name":"inventory","success":true,"typeCount":2,"valueCount":3,"module":{...}}

IR Module Content in Output

JSONL output includes the full IR module structure:

{
  "name": "api",
  "success": true,
  "typeCount": 1,
  "valueCount": 2,
  "module": {
    "types": [{"name": "User"}],
    "values": [{"name": "GetUser"}, {"name": "CreateUser"}],
    "sourcePackage": {
      "namespace": "mycompany",
      "name": "api"
    }
  }
}

Diagnostic Pipeline

The WIT pipeline emits structured diagnostics for type conversion issues.

Diagnostic Codes

Code	Description
WIT001	Integer precision lost (e.g., u8 → Int)
WIT002	Float precision lost (f32 → Float)
WIT003	Unsupported type: flags
WIT004	Unsupported type: resource
WIT005	Round-trip validation mismatch

Viewing Diagnostics

# Verbose output shows all diagnostics
morphir wit make api.wit -v

# JSON output includes diagnostics array
morphir wit make api.wit --json

{
  "success": true,
  "typeCount": 1,
  "valueCount": 2,
  "diagnostics": [
    {"severity": "warn", "code": "WIT001", "message": "lossy mapping: u64 → Int"}
  ]
}

Strict Mode

Treat warnings as errors for CI enforcement:

# Fail on any warnings
morphir wit make api.wit --warnings-as-errors

# Fail on unsupported constructs
morphir wit make api.wit --strict

Round-Trip Validation

The build command validates that WIT → IR → WIT conversions are semantically correct:

morphir wit build api.wit -o regenerated.wit

SUCCESS Compiled WIT to Morphir IR
  Types: 1, Values: 2
VALID Round-trip validation passed

If the round-trip produces different WIT (due to lossy conversions):

WARN Round-trip produced different output (lossy conversion)

What's Coming Next

Future CLI Preview releases will include:

• Full IR JSON parsing for morphir wit gen
• Additional WIT types - flags, resources
• IR emission strategies - configurable JSON output formats
• More backends - Scala, TypeScript, Go generation from WIT

Stay tuned to the Release Notes for updates.